高精度电涡流传感器的标定研究

Calibration of High Precision Eddy Current Sensor

线性度是传感器静态特性的一个重要指标,为减小电涡流传感器的非线性误差,提高其测量精度,对电涡流传感器的输出结果进行标定。给出了电涡流传感器输出电压与探头线圈和被测金属导体之间距离的关系式,在满足的±0.5mm量程,分辨率达到万分之一的前提下,分别采用直线拟合法和曲线拟合法对电涡流传感器进行标定。实验结果表明,利用曲线拟合采用3阶多项式拟合要比直线拟合法线性误差更小,非线性误差由17.19%降到0.7%。

Linearity is an important indicator of the static characteristics of a sensor. In order to restrain the nonlinear error and to improve the accuracy, calibration of precision eddy current sensor is studied. The relationship between the output voltage of the eddy current sensor and the distance from the probe coil to the measured metal conductor is inferred. In the case that the range is ±0.5 mm and resolution reaches one ten thousandth, the precision eddy current sensor is calibrated respectively through Straight line fitting method and Curve fitting method. Experimental results show that, the Curve fitting method is better than the Straight line fitting method, and the nonlinear error is improved from 17.19% to 0.7%.